Re: Comments on draft-yourtchenko-colitti-nd-reduce-multicast

[Ole Troan <[e-mail]>]

Hemant,

> The only means in ND to specify all destinations as off-link is to have the RA include no PIO and have the A-bit cleared.   The hosts use DHCPv6 for address assignment.   This is the NBMA ND link model.  The router also supports a DAD Proxy.

RFC4861:
   Note, however, that a Prefix Information option
   with the on-link flag set to zero conveys no information concerning
   on-link determination and MUST NOT be interpreted to mean that
   addresses covered by the prefix are off-link.  The only way to cancel
   a previous on-link indication is to advertise that prefix with the
   L-bit set and the Lifetime set to zero.  The default behavior (see Section 5.2)
   when sending a packet to an address for which no
   information is known about the on-link status of the address is to
   forward the packet to a default router;

the effect of an unset L-flag is that all traffic is sent to the default router. redirects can be used to indicate that the destination is on-link. you are wrong with regards to the A-flag. and you are wrong with regards to addresses having prefixes.
that's an unfortunate short-hand we are using, but they are still different things. an address does not have a prefix length.

cheers,
Ole